Platelet glycoproteins IIb and IIIa associated with blood monocytes are derived from platelets

Platelet glycoprotein IIb/IIIa (GP IIb/IIIa), the receptor complex for fibrinogen, has been regarded as a megakaryocyte/platelet lineage- restricted antigen. Recently, however, it has been reported that GP IIb/IIIa is expressed in blood monocytes. Studies were performed to establish the origin and immunological characteristics of monocyte- associated glycoproteins IIb and IIIa (GPs IIb and IIIa). Preparations of blood monocytes containing varying platelet-monocyte ratios were metabolically labeled with [35S]methionine with the expectation that any newly synthesized GPs IIb and IIIa would be monocyte-derived, since platelets have only rudimentary protein synthetic apparatuses. Analyses of sodium dodecyl sulfate (SDS) gels of homogenates of cell preparations containing from 200 to 5:1 platelet-monocyte ratios revealed that unlabeled GPs IIb and IIIa were readily immunoisolated using protein A-Sepharose immunobeads. However, fluorographic analyses of the same cell preparations pulse-labeled with [35S]methionine failed to demonstrate synthesis of GP IIb or IIIa. Additionally, no GP IIb or IIIa was detected when immunoisolation was carried out in pure preparations of monocytes containing less than 1:100 platelet-monocyte ratios and SDS acrylamide gels were stained by the sensitive silver stain method. Furthermore, heterologous polyspecific antisera and two monoclonal antibody preparations against GPs IIb and IIIa, which bound to platelets, failed to bind to monocyte membranes. Thus, evidence was presented that indicated that monocytes do not synthesize platelet GPs IIb and IIIa and that detection of these molecules in blood monocyte preparations reflects platelet contamination.     

Diminished concentrations of insulin-like growth factor I in cystic fibrosis

Cystic fibrosis is frequently accompanied by a catabolic condition with low body mass index caused by a number of disease complications. Insulin-like growth factor-I (IGF-I) is an anabolic hormone and an important marker of nutritional status, liver function, and linear growth. Available data on IGF-I in cystic fibrosis are sparse and conflicting. From 1990-3, 235 of our 240 patients (114 males, 121 females, median age 16.2 years, ranged 0.1-44.0 years) had IGF-I measured once by radioimmunoassay. IGF-I was significantly reduced compared with a healthy Scandinavian control population: mean (-2 SD to +2 SD) IGF-I SD score was -0.97 (-3.7 to 1.7) in males and -0.67 (-3.2 to 1.9) in females. Height SD score was -0.95 (-3.3 to 1.4) in males and -0.81 (-3.2 to 1.6) in females. In patients who were still in the growth period a significant correlation of IGF-I SD score to height SD score (r = 0.28, p < 0.001) was found. The low IGF-I concentrations may reflect the catabolic state of many patients with cystic fibrosis and play a part in their abnormal growth pattern.     

Asymptomatic intracardiac thrombus in steroid-sensitive nephrotic syndrome

Arterial and venous thrombotic events can lead to severe complications in the nephrotic syndrome, but may remain clinically silent in a substantial proportion of patients. Intracardiac thrombi associated with multiorgan thrombosis have been described in autopsy cases of the earlier literature, but have never been documented in vivo. We here report an asymptomatic intracardiac thrombus in a child with frequently relapsing steroid-sensitive nephrotic syndrome and a ventricular septal defect. Received: 7 May 2001 / Revised: 19 November 2001 / Accepted: 24 November 2001     

Written language clues to cognitive changes of aging: an analysis of the letters of King James VI/I

Reductions in language complexity normally occur in older adults because of decreased working memory and rate of language processing. Comparative measures can reveal whether linguistic change is due to normal aging or dementia. Linguistic analysis of a series of letters of King James, 1566-1625, investigate whether he exhibited a normative or atypical pattern of change. Fifty-seven letters from the years 1604 to 1624 were analyzed. Data modeling reveals a quadratic pattern of decline in written language complexity with increased diversity of vocabulary corresponding to historical reports of illness around 1618-1619. This investigation demonstrates how language analysis can provide valuable insight to normal and pathological cognitive changes of aging as well as to the understanding of historical figures.     

Effect of commuter cycling on physical performance of male and female employees

PURPOSE: The purpose of this study was to determine the effect of commuter cycling on physical performance. Eighty-seven male and 35 female employees volunteered to cycle regularly to their work. METHODS: Sixty-one participants went commuter cycling for 1 yr (cycling group); the others cycled only in the second half year (control group). A maximal exercise test on a cycle ergometer was carried out at the start of the study, after 6 months, and after 1 yr to measure maximal external power (Wmax) and maximal oxygen uptake (VO2max). RESULTS: After the first 6 months of commuter cycling, with a mean single trip distance of 8.5 km and a mean frequency of more than three times a week, a significant increase of 13% was found in the Wmax per kilogram body weight (Wmax x kg(-1)) in both sexes of the cycling group. The improvement in VO2max x kg(-1) was significant for the male participants (6%) but not for the female participants (-2%). At the end of the second half year, the control group also showed a mean gain in Wmax x kg(-1) of 13%. Their VO2max x kg(-1) declined in the first half year, but this was counteracted in the second half year. A dose-response relationship was found between two independent variables and the physical performance; the lower the physical performance at the start of the study and the higher the total amount of kilometers cycled, the higher the gain in Wmax. For subjects with a low initial fitness level, a single trip distance of only 3 km turned out to be enough to improve physical performance. CONCLUSION: Commuter cycling can yield much the same improvement in physical performance as specific training programs.     

Positive and negative life events: the relationship with coronary heart disease risk factors in young adults

OBJECTIVE: to investigate the influence of positive and negative life events (including daily uplifts and daily hassles) on several biological and lifestyle coronary heart disease (CHD) risk factors. METHODS: from the Amsterdam Growth and Health Longitudinal Study (AGHLS), a cross-section sample of 207 males and 231 females aged 32/33 years was used. RESULTS: hardly any associations were found between both positive and negative life events and biological CHD risk factors. On the other hand, daily uplifts and positive life events were positively related to lifestyle. For both positive and negative life events coping behaviour played a role in these relationships. Furthermore, it was shown that the associations of health-related variables with daily uplifts and hassles were comparable to those found for major positive and negative life events. CONCLUSION: This study could not fully determine whether or not different mechanisms play a role in the health benefits of positive life events compared to the health burdens of negative life events.     

Duane retraction syndrome, a new feature in 22q11 deletion syndrome?

A female child with Duane retraction syndrome is described. A microdeletion on chromosome 22(q11) was discovered using FISH analysis. It is postulated that Duane retraction syndrome might be a new feature in 22q11 deletion syndrome.     

Physiological anticoagulants and activated protein C resistance in childhood stroke

Immunological and functional protein S, protein C and antithrombin III levels and anticoagulant responses to activated protein C were measured in 24 patients with stroke in childhood. No hereditary deficiencies were found. The protein S levels in healthy controls of younger age did not differ from the adult levels. For optimal screening of protein S deficiency, measurements using functional as well as immunological assays are recommended. Appropriate criteria for the diagnosis of the deficiencies must be carefully applied if unnecessary anxiety and inappropriate treatment of children are to be avoided.